Major League Baseball changed majorly this year, with the addition of three little words to the rulebook: "Expanded replay review." Now, instead of charging the field and kicking dirt at umpires' shins to protest certain calls, team managers can request that officials review video of the play. If the replay shows the call was clearly wrong, it is overturned.

Managers are still arguing over ball-strike calls at the plate, which the new rule does not cover, and ejections of players, managers and coaches from games were actually up in May, compared to the same month last year. But so far, roughly half of the challenged out-safe calls reviewed by video have been overturned. Score one for objectivity (we suppose).

When it comes to technology making its way onto the baseball diamond, expanded replay review is just the tip of a very large iceberg. This season, Major League Baseball Advanced Media (MLBAM, or just "BAM" as it's known inside baseball) is rolling out new technology that analyzes plays in a way that would have made legendary broadcaster Harry Caray exclaim, "Holy Cow!"

It lacks a fancy name (so far) but MLBAM's tracking technology employs a combination of radar, high-end cameras and data-crunching algorithms to elucidate any given play with remarkable accuracy and detail. Take, for example, a recent double play that occurred in a game between the New York Mets and St. Louis Cardinals. Here's the series of events: Cardinals batter Jon Jay hits a grounder down the middle, which Mets shortstop Ruben Tejada picks up on a dive and tosses to second baseman Daniel Murphy, who tags the base, where Cardinals base-runner Jhonny Peralta is out, and then throws to first, where Jay is out.

Viewed through the player tracker, action slows and on the screen is a trove of metrics, starting with Mets pitcher's Jenrry Mejia's 91.4 mile-per-hour (mph) throw (not to be confused with its "perceived velocity" of 91.6 mph), which is hurtling toward Jay at 2,193.34 rotations per minute. Jay hits the ball with an exit velocity of 102.16 mph as Tejada, who is 27 feet, 9.65 inches from the bag, jumps into action 0.15 seconds later, sprinting 16 feet, 7.36 inches, to pick up the ball. We could go on, but you get the picture, as illustrated below.

MLBAM, which offers a range of digital tools to keep baseball fans engaged with the game, including the popular At Bat app, is testing tracking technology at three parks this season: The Mets' Citi Field, the Milwaukee Brewers' Miller Park and the Minnesota Twins' Target Field. The organization plans to install the system at all 30 ballparks next year.

Radar technology from Trackman, known mostly for products and services that golfers use to improve their swing, is used to capture the speeds, angles, spins and movements of the baseball and the players. That mountain of data is then run through algorithms developed with the help of Claudio Silva, professor of computer science and engineering at the New York University Polytechnic School of Engineering. "The idea is to be able to track players at as high-resolution as we can and as automatically as we can," he says, although the goal is not merely to track movements, but to collect metrics.

The process generates data no one has ever had access to, Silva says, including the movements of outfielders. This might seem mundane, but correlating each outfielder's exact position with each pitch of the ball and each batter's performance, over time, can help managers and players see patterns emerge. In the end, instructing a center fielder to play two feet to the left when certain pitchers throw to certain batters could mean more successful fielding. And that could win games.

End game

None of this data would mean much to baseball fans were it not for the on-screen annotation, provided by broadcast graphics company ChyronHego, which turns the data into second-by-second action. Thus far, the player tracker output is shown for select plays at the three pilot ballparks, via the MLBAM site and on game analysis shows. Once the technology is deployed at all parks, however, MLBAM hopes to use the tracker technology on each play. Broadcasters will be able to run player tracker on significant plays during the game, via replays.

To someone who knows little about the sport of baseball, this obsessing over numbers might sound, well, obsessive. Certainly, the data is a treasure for talent scouts, team managers and even players. And in fact, statisticians have always been among baseball's biggest fans. It's not hard to find someone sitting at a game with a scorebook and pencil in hand, listening to the game commentary via headphones and, during short breaks, scrolling around a baseball app on her phone.

Vince Gennaro, an MLB team consultant and president of the Society for American Baseball Research, says the availability of increasingly rich metrics only serves to make die-hard fans dive deeper into stats -- and to defend or criticize coaching decisions more earnestly. "I think we found a way to make the baseball appetite insatiable," he says. "The deeper you can go, in terms of information, you actually prime the thirst for it."

The backstory for all this interest in the game, he thinks, is linked to how we play it (or don't).

"We're in an era now where it has a lot to do with youth baseball, which is so structured and if you're not playing travel ball by 10 years old, you're not in the funnel and you won't compete, long term. So, a lot of the love of baseball, the passion, is being taken up through the data explosion," he says. Tracker technology will only serve to amplify interest that Sportsvision's Pitcher f/x system, which shows statistics for each pitch, started generating in 2009.

"The rock stars used to be the players, and to an extent, they still are," Gennaro adds. "But the [general managers] are the new rock stars. Everyone watches them, and everyone is doing shadow analysis. It has become part of America's pastime. I think technology has fed right into that."